From: Alexander Dahl <ada@thorsis.com>
Date: Fri, 20 Apr 2018 13:29:30 +0000 (+0200)
Subject: tools: mkenvimage: Fix read() stdin error handling
X-Git-Tag: v2018.05-rc3~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3559028cb2840cc283652f4b7e4e1b457e6ec6a5;p=platform%2Fkernel%2Fu-boot.git

tools: mkenvimage: Fix read() stdin error handling

On success read() returns the number of bytes read or zero for EOF. On
error -1 is returned and errno is set, so the right way to test if read
had failed is to test the return value instead of errno.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---

diff --git a/tools/mkenvimage.c b/tools/mkenvimage.c
index 8eee72e..716cb73 100644
--- a/tools/mkenvimage.c
+++ b/tools/mkenvimage.c
@@ -168,7 +168,7 @@ int main(int argc, char **argv)
 				return EXIT_FAILURE;
 			}
 			readbytes = read(txt_fd, filebuf + filesize, readlen);
-			if (errno) {
+			if (readbytes < 0) {
 				fprintf(stderr, "Error while reading stdin: %s\n",
 						strerror(errno));
 				return EXIT_FAILURE;